DESCRIPTION: (Adapted from applicants abstract) This is a 5-year longitudinal study of three ethnic groups of midlife women, with baseline data collection beginning prior to the experience of menopause and continuing every two months during their perimenopausal experience. There are three primary aims: Aim #1 is to describe the bio-psycho- social-cultural environment of three ethnic groups of midlife women (African, Mexican, and European Americans) and the patterns of change over time in biological factors (serum FSH, menstrual cyclicity, menses flow, serum iron levels, body fat composition, sleep fragmentation, and nocturnal body temperature). Psycho-social factors (socioeconomic status, family structure, satisfaction with primary relationships, symptom distress, and social support) and ethnic/cultural factors will also be examined (premenopausal attitudes toward menstruation, menopause, and aging; meanings and expectations of midlife). Aim #2 is to compare these bio-psycho-socio-cultural factors for women with severe perimenopausal symptom experiences to women who are not experiencing severe symptoms during their menopausal transition. Aim #3 is to explore symptom responses and health-seeking behaviors in relation to health outcomes and health service use. Approximately 900 women between 40-45 years of age will be screened to enroll 450 African, Mexican, and European Americans who meet inclusion criteria (regular menstrual cycles, no hormone use, no surgical menopause, and low FSH levels). They will be recruited directly from community-based churches and indirectly from their children and grandchildren in public schools in three San Francisco Bay Area counties. Qualitative and quantitative data will be collected every two months by telephone and every 6 months in the home over a 4-year period. Analyses plans include repeated measures analysis of variance to examine changes over time (Aim #1), Chi-square statistics for prevalent biopsychosocial factors related to presence of severe symptoms (Aim #2), and logistic regression to explain presence or absence of health care use (Aim #3). In addition, 20% of the sample, selected at random from the participants (30 from each ethnic group), will have intensive interviews taped, transcribed, and text analyzed to identify themes pertaining to personal meanings of midlife experiences. The qualitative data will inform and enrich the ethnic dimension of the quantitative data obtained from the standardized instruments.